Apparatus for teaching the addition and subtraction of whole numbers through the use of objects are known. For example a U.S. Pat. No. 5,529,497 of Bigold. As disclosed, the apparatus includes a sheet with three containers across in a row, the containers being separated by a mathematical sign (a plus sign or a minus sign), and the second and third containers being separated by an equal sign, and a plurality of objects of similar shape but with distinctive markings. Some of the objects are placed in the first container, and others in the second container. The third container may then be filled by a child with the object representing the result of the mathematical process to be performed.
A more recent approach to a teaching apparatus and method for visually representing mathematical expressions is disclosed in a U.S. patent of Dreyfous, U.S. Pat. No. 5,820,381. As disclosed, an apparatus and method for teaching mathematical expressions includes a plurality of four-sided members that represent the variables of factors of a mathematical expression. Each four sided member has a different area representing a different variable in the mathematical expression. The apparatus enables a math student to visualize the rules that apply to mathematical expressions. The four-sided members include a first side having a first color, a second side having a second color different from the first color wherein the first side represents a positive number and the second side represents a negative number. Alternatively, the sign may distinguished by varying surface roughness of the members. The four sided members can be used for teaching by illustrating simple multiplication and division, multiplication, division and factorization of polynomials, linear expressions including equations including inequations and absolute value, and systems of linear equations.
A more recent approach to teaching addition and subtraction of positive and negative numbers by a game is disclosed in a U.S. patent of Frieman, U.S. Pat. No. 6,926,530. The patent disclosure is based in the Null Theory of Addition and Subtraction Positive and Negative Numbers. The apparatus comprises (a) a plurality of positive units, (b) a plurality of negative units, (c) a demarcated playing zone, and (d) a means for measuring the number of free positive units and free negative units within the demarcated playing zone. While the demarcated playing zone, free positive units combine with free negative units zone to form null units with each null unit comprising an equal number of positive units and an equal number of negative units. Each null unit preferably comprises one positive unit and one negative unit.
A more recent approach to teaching addition and subtraction of positive and negative numbers by a game is disclosed in a U.S. patent of Fulton, Jr., U.S. Pat. No. 7,182,342. The patent discloses a game for teaching arithmetic skills involves having a play spin a wheel twice, the first time determines the arithmetic operation to be performed and the first number in the second spin determines the second number. The player then moves his or her game piece according to the results of the arithmetic operation, if the player correctly performs the operation and obtains the correct result. The player will forfeit his turn if he incorrectly performs the operation. Rules of the game control the direction of movement of the game pieces and the number of spaces the game piece can be moved on any one turn. A winner is determined by the first player to reach a finish position.
Notwithstanding the above, it is presently believed that there is a need and a potential commercial market for an improved game for teaching addition and subtraction of whole numbers.